/// <summary>
/// Visits all the nodes in a graph. Used when the maximum node identifier is known
/// </summary>
/// <param name="startNodes">Initial nodes</param>
/// <param name="visitor">Visitor object</param>
/// <param name="maxNodeId">Maximum node identifier value in the graph</param>
/// <remarks>
/// A node is only visited once all its input nodes have been visited first.
/// </remarks>
public static void Walk( IEnumerable<IGraphNode> startNodes, IGraphNodeVisitor visitor, int maxNodeId )
{
if ( startNodes == null )
{
throw new ArgumentNullException( "startNodes" );
}
if ( visitor == null )
{
throw new ArgumentNullException( "visitor" );
}
visitor.StartVisiting( );
NodeStatus[] nodeStatuses = new NodeStatus[ 32 ];
Queue<IGraphNode> nodeQueue = new Queue<IGraphNode>( );
Enqueue( nodeQueue, startNodes, ref nodeStatuses );
try
{
while ( nodeQueue.Count > 0 )
{
IGraphNode node = nodeQueue.Dequeue( );
if ( nodeStatuses[ node.Id ] == NodeStatus.Visited )
{
// Guards against cyclic graphs
continue;
}
// Check that the current node can be visited
if ( !CheckNodeStatus( nodeQueue, node, ref nodeStatuses ) )
{
// It can't (an input node has not been visited yet)
nodeQueue.Enqueue( node );
continue;
}
// Enqueue all output nodes of the current node
Enqueue( nodeQueue, node.OutputNodes, ref nodeStatuses );
// Visit the current node
visitor.Visit( node );
nodeStatuses[ node.Id ] = NodeStatus.Visited;
}
}
finally
{
visitor.FinishVisiting( );
}
}
/// <summary>
/// Visits all the nodes in a render node graph.
/// </summary>
/// <param name="startNodes">Initial nodes</param>
/// <param name="visitor">Visitor object</param>
/// <remarks>
/// A node is only visited once all its input nodes have been visited first.
/// </remarks>
public static void Walk( IGraphNode[] startNodes, IGraphNodeVisitor visitor )
{
Walk( startNodes, visitor, 32 );
}